Three Puzzles
by Kitkatlaugh
Summary: When John's lively little cousin, Kate, comes to stay with him and Sherlock, things get interesting. Can Kate solve the puzzle that is Sherlock Holmes, or will something happen before she gets the chance? Only time will tell. WARNING: references to substance abuse
1. Katherine Watson

Ch1

It was a typical cloudy day in London. The roads were busy with cabs and tourists, and the residents of 221b Baker Street were bored. John sat, tapping at his computer while Sherlock lied on the couch, mumbling incomprehensible strings of who knows what. Their previous case had just been closed, and the two men had absolutely nothing to do.

"John, did you get a new girlfriend?" Sherlock groaned from across the room, peering out the casement. "You need to warn me before you have people over!"

John only smirked, knowing that this wasn't even half the reaction that his flat mate would have when he found out who this woman actually was and what she was doing here.

As if on queue, the doorbell rang and John anxiously jumped up to greet their visitor. He opened the door to a young woman in her early thirties. As soon as she was in John's sight, he swept her off of her feet into a tight hug.

Kate hadn't see John in five years, easily, and once she had told her cousin that she would be moving to London, he had insisted that she stay with him and his infamous flat mate, Sherlock Holmes. She had reluctantly given in to his request, only because he had offered. She didn't want to become a pain, something that she feared would happen.

Kate and her cousin walked back into the inviting flat, John carrying Kate's bags as he only saw proper and had once again insisted.

"Sherlock, this is Kate. She'll be staying with us for a while."

The consulting detective quickly looked over the woman standing in his living room.

"Since when have we agreed that your girlfriends could stay with us?"

John laughed and set down Kate's bags.

"I may have left out an important detail. She's my cousin, Sherlock, not my girlfriend."

Sherlock felt foolish that he hadn't noticed the resemblance earlier, looking her over once more to see that it was actually quite obvious looking. The woman had John's light brown hair and chocolate eyes. She was short, standing at only about 5'2, another similarity between her and John. Still, for John's sake he decided not to judge her just yet. He assumed that he wouldn't like her, but with her being the cousin of his only friend, he decided he'd judge her more critically later, if there was a later, which in the case that he got his way, there wouldn't be.

"No John, she's not staying with us. We didn't talk about this," he muttered, remaining monotonous and without expression.

"Sherlock, she _is_ staying with us. She's just arrived in London and we will give her a warm welcome!"

"You know how I am with people. This won't work out well and we both know that."

"Kate isn't just any normal person, she's my little cousin, and she's staying with us. That's final."

"Fine," replied Sherlock, immediately returning to peering out the casement as if nothing had ever happened.

Meanwhile, Kate was still just standing there, not quite sure how to react to the situation that had just played out in front of her. Of course, she loved John, but Sherlock just seemed… difficult. Kate was a kind, mostly honest, and overall likable person, but befriending her cousin's flat mate seemed like it would prove to be more than difficult than she had been expecting.

She would get through it though

After all, she was Katherine Watson.


	2. A Temporary Home

Ch2

"Come on, then, Kate!"

John's voice broke her out of her thoughts as he picked up her bags and headed toward his room. Kate spun around and followed him, eager to see where she'd be staying.

"You get to move into my room while you're here. There's a bathroom across the hall, and the bedroom door locks, so Sherlock shouldn't be able to bother you."

After deciding that she probably didn't even want to know why Sherlock would bother her while she was in her bedroom, she glanced around the room. It looked cosy. It was very plain, with light blue walls, a twin bed in the corner, a dresser, closet, small bookshelf, and even a little nightstand.

Overall, Kate loved the room, but her stubborn selflessness got the better of her and she walked up to John, took back her bags, and set them on the floor next to her.

"No, John. You're being kind enough letting me stay here! The least I can do is allow you to have your own room!"

"Kate, you're staying here. I'm not discussing this with you. You're my cousin and I love you. You wouldn't be able to get any sleep on the sofa anyway. Sherlock would just keep you up all night."

John was being John, and nothing Kate could say was going to change his decision now. He felt that it was his responsibility to keep Kate safe and comfortable while she was staying at 221b, and the army doctor was confident that he would.

Finally realizing that arguing would get her nowhere, Kate reluctantly set down her bags. She pulled John into a hug and smiled to see that even though her cousin was short, she was still shorter.

"I love you too, John. Thank you, for all of this," she spoke into his sweater.

He looked down at her and pulled her slightly away from him by the shoulders so that they were making eye contact.

"Hey, it's my job. You know you can always talk to me right?"

"Yes, John," she replied and smiled.

"And if Sherlock says or does anything to offend you, you just tell me. Got it?"

"John, I'm not a little girl anymore. I can take care of myself," her voice sounded gracious, but warning, as if to prove her point.

Her cousin nodded at her, immediately understanding that he was being a bit too overprotective.

"If you don't mind, I think I'm just gonna have a little nap. I think it's the jetlag, so I should be better by morning. Just need to reset my circadian clock!"

John looked at Kate uncertainly before nodding and making his way out of his room.

"I'll be here in the living room if you need anything," John spoke gently.

It was kind of cute in the way that he obviously wanted to spend more time and catch up with his cousin, but his doctor side got the better of him. Kate needed rest, and John would let her have it.

Kate smiled wearily and looked in the mirror hanging above the dresser. She couldn't remember the last time she had smiled this much. She was actually smiling, and it felt amazing! Tears threatened to slip down her cheek, but Kate tore her head away before they could escape and she started unpacking. She wouldn't let emotions take control. What good were they? Sure, caring and loving had never hurt her before, but sadness and anger were just useless. They wouldn't let her think and they took control of everything. Kate wouldn't have that; she needed control of herself. Once she had finished, she pulled on a pair of pyjamas and crawled into the bed. Her pillow smelled nice, like cinnamon and rubbing alcohol, just the way she had remembered John.

She fell asleep smiling, and that night she dreamt for the first time in years. Kate had been struggling with depression for a few years, and she had only moved to London to escape all of the old memories that had haunted her back in Cardiff. She hadn't expected her new life to start like this, meeting a mysterious detective and reuniting with a cousin that loved her with all of his heart. This new life wasn't half as bad as she had thought that it would be, but it was about to get so much better.


	3. High-Functioning Sociopath

Ch3

The next morning started with a bang, literally. It was about 10 am and Kate was jolted awake as a tremendous noise that sounded suspiciously like a gun rang through the flat. She sprang out of bed and ran into the living room to find the source of the sound. Sherlock Holmes was lying on the sofa, holding a gun that had just caused one of the many holes in the wall. However, instead of blowing her top like any other human would do, she just stood patiently in the doorway.

"What did you do?" she asked, obviously annoyed at being wakened.

The consulting detective didn't even open his eyes, he only waved his hand through the air as if to shoo the young woman away.

"What did you say to him?" Kate pressed, obviously not planning on giving up any time soon.

Sherlock, only faintly aware that he was being spoken to, simply replied, "Sorry?"

"Well, you obviously said something to him. He's not here and you're firing holes in your wall! My cousin is a fine man, and although he can have a temper, he doesn't often show it. You actually made him walk out of his own flat so that he could manage his frustration. You must have said something that actually got to him, so what was it? What did you say?" The room was silent.

After a few moments Sherlock decided to reply. "Don't concern yourself; he should be back in a matter of minutes."

Kate just stood there, trying to track the paths of this mysterious man's thoughts. He was a puzzle to her, and a very unique one at that. She had never met anyone quite as complex as Sherlock Holmes, but she had never come across a puzzle that she couldn't solve either. Never mind, that puzzle could wait for a better time.

With John being out and Sherlock being, well . . . Sherlock, this was the perfect opportunity for Kate to look around the flat a bit more. She started with the kitchen, if you could call it that. The only neat thing in the room seemed to be a pack of needles lying in the sink. There were papers and test tubes and beakers and even a large microscope scattered on the table that sat in the center of the room. Once, it may have actually been used for eating on, but those days were long gone.

Also, confirming her suspicion, the refrigerator wasn't much better. The only difference was that instead of being filled with a variety of unusual equipment, this was full of specimens. Not just any normal specimens either. There was a blue pig's liver soaking in some strange clear liquid that judging by the smell of it definitely wasn't water; and there was also half of a human toe sitting in another liquid that looked and smelled suspiciously like formaldehyde.

Resisting the urge to take out the toe and put it into the microwave to see what would happen, Kate walked out of the kitchen to a bookshelf on one side of the room. She pretended not to notice Sherlock following her with his eyes, almost looking surprised that she hadn't had some sort of extreme reaction to what she had seen in the kitchen.

He had expected her to have shouted or screamed like anyone else who had seen his experiments, and after not hearing anything, he had actually wondered if she had fainted with shock. When she had walked out of the kitchen like it was any normal kitchen, he had, to an extent, failed in hiding his surprise.

Kate began scanning the shelf as Sherlock regained his composure. Luckily, she was an avid reader, and quickly found a book on psychosocial development. She had always loved psychology, and having quite a bit of personal experience with it, knew a decent amount about it.

The younger Watson lied down on the sofa and opened the book to read. Sherlock had been typing away on one of his many computers, but suddenly stopped, his curiosity getting the better of him as always. The consulting detective made him way over to a chair that he dragged to stand in front of the couch. Kate didn't notice him, already absorbed in Erik Erikson's psychological theories.

"When were you diagnosed?" he asked suddenly.

Kate immediately set down her book and sat up straight, staring at Sherlock with anger, curiosity, and maybe even a hidden hint of interest.

When the young woman didn't respond, he tried again.

"Your depression, when was it diagnosed?"

"When I was ten years old," she murmured, almost in a whisper. "How did you know?"

"You obviously have an interest in psychology," he started, gesturing toward the book she was holding, "Out of the various subjects of reading that I have on my shelf, you chose that one. You don't seem the type to just pick a book off the shelf either. Most of the time, interests in psychology begin with a personal connection. John's told me that he has mental disorders running in his family, so it was reasonable to work my way up from there. At first I suspected anxiety, but it doesn't quite add up. Although you have the symptoms of anxiety, there's something else. You're smiling too much. It's as if you haven't smiled in a long, long time, and you're just now remembering how wonderful it feels. Also, this morning you seemed greatly concerned about John's emotions. From what I've seen, I suspect that you try to protect others' emotions because you can't seem to handle your own. That points to depression," he stopped when he noticed that she wasn't paying attention. She was deep in thought staring into space. Sherlock had never been in this situation; it was always him in Kate's place and someone else in his, so, not quite sure how to react, he waited a few seconds and then decided to change the subject.

"That's a good book, one of my favorites actually."

Kate snapped back into focus and acted like nothing had ever happened. It was as if she and Sherlock's previous conversation had no use here and it had been tucked away in a small corner of Kate's mind.

"You like psychology?" she asked with a new confidence.

Sherlock nodded, as if it were obvious.

"What's your personal connection?"

"I'm a high-functioning sociopath," he muttered, stating it like it was a chore and he had to explain it to someone every day.

Kate sat there on the sofa looking into a pair of piercing blue eyes before only speaking three words. Little did she know these three words would have quite an impact on the mysterious detective sitting before her.

"No you're not."


	4. Deductions

Ch4

The sound of the door creaking open broke the silence between the two adults. John hung up his jacket and turned toward his living room, the look on his face making it clear that he had _not_ expected to see what he currently was. His cousin, who hadn't even been in London for a day, was sitting on the sofa having what seemed to be a conversation with Sherlock Holmes. No one appeared to be injured, Kate wasn't in tears, and overall, neither party looked like they really wanted to strangle the other.

Not surprisingly, Kate was the first to actually start talking again.

"Morning, John! How was your walk?"

John looked at her blankly, still a bit in shock.

"Uh, yeah, yeah it was good! Sorry, morning! How was your sleep?"

Kate stood up and walked over to John, smiling giving him a quick hug.

"It was wonderful," she stated, every bit of it true. "I also had quite an adventure this morning! I discovered what someone could possibly call your 'kitchen', along with the liver and piece of human toe. After that, I had an interesting conversation with Mr. Holmes, here."

John's brow furrowed with worry when his cousin brought up the conversation that had occurred between Sherlock and her.

"Has he done anything stupid yet?" the older Watson asked hesitantly.

"You mean the deductions?" Sherlock chimed in. "No, I wanted to wait until you were back for that part."

John muttered something under his breath and his cousin looked toward him in confusion. He wondered how she would react when Sherlock deduced her. What's more, he wondered how _he_ would react. He didn't know everything about Kate, and surely she had some skeletons in her closet. The question was, how bad were those skeletons, and once John had seen them, would he ever look at his innocent little cousin in the same way?

"Just get it over with," John said reluctantly.

"Brilliant!" Sherlock started, his face breaking into a devilish grin. He turned to Kate and continued. "John here has already told me quite a bit about you, so let's try something more interesting. How about something he doesn't know?"

_"He just had to go straight there!_" John thought, closing his eyes with frustration. Kate was just looking curiously at Sherlock, who was now squinting at her.

"Recently single, dancer, plays the piano, writes quite a lot, high IQ, multilingual, two brothers, risk taker, and extremely experimental when it comes to science, which you enjoy immensely. I feel like there was one more…" the consulting detective trailed off.

John sighed with relief; nothing had been disastrous. Maybe Kate was just one of those people who didn't have skeletons!

"Oh yes, substance abuse, that was it! You're still recovering from a few addictions!" Sherlock added.

Kate stood where she was, jaw set. There they were, the skeletons. The wheels in John's mind were turning and his head started to spin. Kate? Substance abuse? That had never even occurred to be a possibility! Then again, it was a shock to find out Sherlock had problems in that area too, but Kate? His baby cousin Kate? He was so wound up in his thoughts that he didn't notice the voices now occupying the room.

"You're one to talk!" Kate shouted.

Sherlock looked at her, wondering how she knew about his own problems. He knew John well enough to know that he wouldn't tell Kate about his previous substance abuse. "What do you mean?"

"Oh, don't act like you don't know! Nicotine, cocaine, morphine, and probably opium too! You shoot the wall! Who shoots the wall for Christ's sake? You need the adrenaline as an alternative to drugs. Not to mention the nicotine patches in your drawers and the syringes. I'm not even going into the syringes! So don't you criticise my previous habits!"

Sherlock raised an eyebrow with an amused look on his face. "What else can you tell about me?" he asked, eager to know exactly how far her deduction skills stretched.

"Oh, I don't know, and I really don't care. Right now, I want to know how you knew what you did."

The consulting detective decided not to push the younger Watson. This was the fun part though, how he did it. It was always how he did it that really got to people! They'd call it blasphemy or magic, but it was really just simple intelligence! At this point, both Sherlock and Kate seemed to have forgotten about John's presence in the room, and their thoughts were taken back to this by quite a shout.

"Substance abuse? SUBSTANCE ABUSE? YOU HAVE GOT TO BE KIDDING ME!" he shouted before storming out of the room. Kate looked guiltily over at him while Sherlock just stared ahead, planning how he's explain to this new woman his deductions.

He started very quickly and spoke with a pace that was very hard to stay with. "_That must be how fast his mind works. It's probably faster." _Kate thought. _"He must have been teased for his intelligence as a kid. He would have wanted to get things out quickly and sound smarter, possibly even more intimidating."_ Kate brushed those thoughts aside and listened.

"The recently single was easy. You're extremely clingy to John, partially because you haven't seen him in a while, but also because you've recently broken up with someone and John is the male figure that is there to support you now. This brings us to your brothers. You're definitely not an only child, and you're probably the oldest which leads us to younger siblings. You're attitude toward men is different then to those who haven't had brothers, there are obvious signs. You are probably close to them, but they don't take you seriously enough for you to go to them casually for emotional help. You had to have had more than one brother because that's also a different relationship then having multiple brothers. I also saw a text on your phone from your brother Charlie. You're balance, the way you sit, and your posture all indicate dancer. Your fingers and calluses say pianist and writer. The callus on your right middle finger has a cut, suggesting you use it quite a lot. You also have chemical stains on your hands from experiments. Your IQ speaks for itself and your accent says multilingual. How many languages?"

"So far five. English, Spanish, Latin, Greek, Russian, and Japanese." Kate replied counting on her fingers. "Wait, that's six. Huh, you never know exactly what you know until you need to use it!"

Sherlock smirked. "Exactly!"


	5. Apologies

**Hello readers! I'm so sorry that I didn't post yesterday! If you've been following my story you know that I post every Saturday. I had a play yesterday, so I had no time. Also, sorry this chapter is so short! Please R&R because reviews are my muse! Thanks!**

**-Kitkatlaugh**

Ch5

The two figures just stood like that for a few minutes, tilting their heads and squinting their eyes as if they wanted to see right into the other's heart and soul.

Kate grinned at her new acquaintance with wonder. Then, her mind went back to John. Her poor cousin John who already had to live with an overly frustrating detective and had just found out that his innocent little cousin had substance abuse issues.

She gingerly turned back toward the hall; leaving Sherlock to do whatever he did while he was alone. Right now, her cousin was a bit more important than someone that she barely knew. She cautiously approached John's room, silently going over what she would say to him. Her knuckles finally hit the door with a light knock, the sound echoing as if it was taunting the younger Watson.

"What?" John snapped from inside his room.

Kate cringed and debated on whether or not she should just come back later. She had to do this now though, he had to know the full story and its extent. She cracked the door open and peeked her head in. John was sitting on the bed, his head resting on his hand and his expression unreadable.

"John, we need to talk," Kate chose her words carefully.

"You think?" her cousin asked sarcastically, frowning up at her.

"John, it's not what it sounds like," she started. John cut her off before she could get any further.

"Really? From what I heard you were involved in some pretty bad stuff, am I right?"

"Yes, but" Kate started again, once again being cut off.

"Drugs? Out of anything out there you chose to go with drugs?!"

"John!" she shouted, making it clear that she wanted to talk. "I stopped! It's in my past and I wish I could go back and undo it, but I can't! You're just going to have to deal with it for now because for me it's already hard enough as it is!" Kate stood in the middle of the bedroom, staring at John. Sure, she wasn't exactly proud of her past, but her cousin would just have to deal with it.

John looked at her sadly, patting the bed next to where he sat as an invitation. Kate hesitantly accepted, plopping down on the bed next to her cousin.

"Hey, I'm sorry. This is just really hard for me, but I can't even begin to imagine how it is for you. I'm not going to ask you what you did, or when you did it, but please at least answer this. Why? Why would you do that?" he asked.

His cousin just sat there for a bit before standing back up and turning to face him. She stared at him solemnly, trying to find a way to explain so that he would understand. "It felt like something indescribable. My mind working at unbelievable pace, knowing more than anyone around me, being in full control of the environment that I was in. There was no pain, or loss, or desperation. No mourning or sulking of any kind. It was just I against the world, and it felt incredible. You know I didn't mean for it to go very far, I just got carried away in the whole of it. The important thing is that I stopped, and I don't plan on starting again." Kate looked at her cousin, searching his face for any traces of emotion, but aside from sympathy, she could find none.

John felt sick. There was really no way to explain the way he felt other than sick. He didn't know what to say or do, so when Kate left the room, announcing she was going out for a bit, he just sat there thinking. It wasn't until he realised exactly what she had said that he abruptly stood up, racing through the hall. "Wait, Kate! Don't enter any suspicious looking vehicles!" he shouted, only to be too late. Kate was already on the streets of London, perfect prey for Mycroft Holmes.


	6. The British Government

**Hi guys! Thanks so much for the reviews! As you know, they're all I get, encouragement wise, so please keep it up! Also, those of you who read this chapter this-morning, it has been updated because someone told me that it should be longer and I full-heartedly agreed. The first chapter with Mycroft definitely needs to be beefy! Let this be a message to readers saying that I DO read all reviews, so any criticism is taken seriously and considered. Thanks again!**

**-Kitkatlaugh**

Ch6

Kate walked down the busy street, a skip in her step as she went. One argument with her cousin wasn't going to ruin her first day in a new city. People bustled about, yelling to each other and pushing past the crowds. Today was a typical London day, the sky was overcast and there was a chill in the air. Kate glanced at her watch. It was only about 11:30, which meant that there was no rush to get back to the flat any time soon. She drifted about, exploring the streets and shops of her new home. The people seemed friendly enough, but there was definitely a fair amount of commotion.

As she exited one of the many shops she had explored, the younger Watson noticed a strange black car pulling up in the street beside her. Deciding to ignore it, she continued walking down the street, this time back towards 221B. A buzz in her pocket momentarily stopped her. Kate paused and took out her phone, reading the strange text that she had just received. The number was blocked, and the message was anything but reassuring. It simply said, "Get in the car."

A bit rattled and paranoid, Kate turned around a few times, looking for anything suspicious. Beside the car that she now saw as creepy, nothing was really out of the ordinary. The best thing to do in a situation like this was probably to contact the police, but, being the strange woman that she was, Kate just continued to walk down the street, a bit faster now.

She stopped mid-pavement and closed her eyes as her phone buzzed yet again, notifying her that she had received another text. She hesitantly took her phone from her pocket, reading the newest message.

"Katherine Watson, I know where you're staying, I know your entire life history, and more importantly, I know how to hurt the people that you love, so I think that it would be in your best interest to get in the car."

Kate swallowed nervously and slowly turned around. The next thing that she did was extremely dull-minded, but she didn't care. This stranger had just indirectly threatened her, and Kate was going to face him or her. The door opened and the younger Watson hesitantly entered and seated herself. The car was very nice, whoever owned it had to have a lot of money. A man was sitting in the driver's seat, most likely a chauffeur. He wore a strange sort of suit and possessed a long and emotionless sort of face. There was also a woman sitting in the seat beside Kate. She had curly brown hair, not very unlike Kate's, and was obviously deeply emerged in her Blackberry.

Seriously doubting any answers would be coming her way, Kate sat quietly for the remainder of the ride. In about ten minutes, they pulled up to a strange abandoned-looking car lot and the other woman got out of the car. Kate followed, less hesitantly now. She really just wanted to know what the heck was going on, and whatever is was, she really just wanted to get on with it!

Finally, after walking through the maze of walls and construction pieces littering the area, Kate saw another man, different from the rest. He was finely dressed with short ginger hair and he held an umbrella in his right hand, the tip resting against the concrete floor.

"Ah, yes, Katherine Watson, you decided to make an appearance after all," the man pronounced smugly.

Not talking was currently the best idea that Kate had, so, that's exactly what she did. She just walked up so that she was about two meters from him and stopped, standing where she was.

"You're much more quiet than I thought you would be," the man started, obviously trying to make conversation.

Kate, however, wasn't going to have that. This man basically abducted her after threatening her privacy, her safety, and the safety of those that she knew. She wasn't here to make conversation with some mad man!

"Can we just get on with this?" she asked smoothly.

The man just raised his eyebrows and nodded at her.

"I understand that you're currently residing at 221B Baker Street?" he asked.

This was an absolutely pathetic waste of time. This man obviously knew where she was staying and most likely knew much more about her than she was comfortable with, yet he still continued to try to make casual conversation with her instead of cutting to the point. He'd probably be asking her what she thought of the weather next!

He was a man of business, but he had other motives as well. Whatever information he'd read about Kate couldn't exactly describe her personality. Sure, it could list strengths and weaknesses, but it couldn't capture the depths of her mind. In order to do that, you had to make conversation with the person. He was trying to get to know her, but why?

"Please don't ask questions that you already know the answer to. Not to bother you, but I really shouldn't stay here for too long, so do you mind getting down to business?"

"Well then, I have a proposal for you. If keep an eye on Sherlock Holmes and report his behaviours and activities to me, and I'll make sure you're treated "well" while you're here in London," he looked at the woman questioningly.

"You want me to spy on Sherlock for money?" Kate asked, holding back a laugh.

"Yes," the man replied.

"Sorry, sir, but I'm not comfortable doing others' dirty work for them. Was there anything else?" Kate asked.

"Then again, you never really have liked to work for others have you?" he asked rhetorically. "No, you can go, but please deliver a message to Sherlock."

Not at all surprised by his first comment, Kate answered his request reasonably. "What would that be?"

"Ask him how his bees are doing."

Kate just briefly nodded before turning her back to the strange man and heading back into the mysterious car. This had certainly been an adventure-packed first day in the city. John would definitely want to hear about this!


End file.
